In recent years, handwriting input is mostly used for a supplement to or a replacement for the conventional keyboard input in electronics devices, since there exist requirements in the follow cases: it is required to cancel the keyboard in order to reduce the volume of the device; it is difficult for special users to use keyboard (e.g. users who have difficulty in typing); and it is required that an accurate input is performed sometimes (e.g., painting, precise drawing), and the like.
As known, the handwriting input is achieved in such a way that a handwriting pen and a tablet (or display screen with handwriting function) are combined. In particular, it is needed to realize the input by writing on a tablet with a corresponding handwriting pen.
However, as known, it is necessary for the user to touch the tablet with the handwriting pen when the user wants to fulfill the handwriting input so as to ensure the completion of the handwriting input, which causes the user to be confined in space when performing the handwriting input thereby giving rise to poor user experience.